21. Principles of Disease

Why are some organisms that constitute the normal microbiota described as commensals, whereas others are described as mutualistic?

This microbe is acquired by humans as infants and is essential for good health. Acquiring a closely related strain causes severe stomach cramps, bloody diarrhea, and vomiting. What is the microbe?

Which of the following is/are true regarding our normal microbiota? Select all that apply.

a. Our normal microbiota is easily disrupted by hygiene practices like hand washing.

b. Our normal microbiota can include pathogens.

c. Normal microbiota compete with pathogens.

d. Normal microbiota may colonize us before we are even born.

e. Normal microbiota changes over time.

f. The normal microbiota that we have as adults is the same as we had as children.

g. The normal microbiota of the gut is similar to that of the skin.

Select the false statement about normal microbiota.

a. They compete with pathogens.

b. They do not include potential pathogens.

c. They make vitamins for the host.

d. They train the immune system.

e. A disruption in their balance can lead to disease.

List the anatomical structures of the human upper respiratory tract.

A microbiome is composed of _____.

a. single, pure populations

b. all organisms in a locale

c. all microbes in a location

d. only the bacteria are considered

When examining the microbiome of the human intestine, you would expect to find how many bacterial species present?

a. one

b. three

c. hundreds

d. thousands

In general, contrast transient microbiota with resident microbiota.

The term dermatophyte refers to_____.

a. pathogenicity

b. where a fungus grows

c. method of spread

d. pigmentation

Which of the following subcutaneous mycoses may exhibit respiratory and cerebral forms?

a. Chromoblastomycosis

b. Mycetoma

c. Phaeohyphomycosis

d. Sporotrichosis